Discharge door for furnaces



Aug. 22, 1933. E. H. RAY 1,923,886

DISCHARGE DOOR FOR FURNACES Filed May 1, 1951 4 Sheets-Sheet l MA/e Aug. 22, 1933. H. RAY 1,923,836

DISCHARGE DOOR FOR FURNACES Filed May 1, 1931 4 Sheets-Sheet 2 jar mw wim Aug. 22, 1933. E, Y

DISCHARGE DOOR FOR FURNACES 4 Sheets-Sheet 3 Filed May 1, 1931 Aug. 22, [933- E, Y 1,923,886

DISCHARGE DOOR FOR FURNACES Filed May 1, 1931 4 Sheets-Sheet 4 e ww m hm. H @m Patented Aug. 22, 1933 STATES 1,923,886 nisonAaoE noon FOR FURNACES Edgar H. Ray, Beaver, Pa., assignor to Jones & Laughlin Steel Corporation, Pittsburgh, Pa, a Corporation of Pennsylvania Application May 1, 1931. Serial No. 534,171

191 Claims. (01. 2636) My invention relates to furnaces and, in particular, to a discharge door for furnaces.

In designing furnaces for heating bulky objects, such as lengths of pipe, considerable difculty has been experienced in providing a satisfactory discharge door. Furnace discharge doors of this type must meet certain requirements, and it is the general object of this invention to provide a door which satisfactorily meets such requirements. In the first place, a furnace-door must fit the opening in the furnacewall rather closely. This necessarily small clearance has heretofore made it dimcult to insure easy operation of the furnace door because the available clearances are not very large, compared to the possible expansion and contraction of the parts of the furnace subjected to heat.

In passing bulky objects, such as pipe lengths, through a furnace and out of a discharge door therein, it will be obvious that numerous difficulties will be encountered. If the pipe is discharged laterally, the door must have a length greater than that of the pipe. The considerable length of door which is necessary introduces a tendency toward warping, and thus prevents an accurate fit of the door in its frame. If the door serves as means for receiving and supporting material to be discharged, it should be pro vided with skidsrand these skids, of course, are connected to the framework of the door. The skids must be artificially cooled or they will transmit the heat from the interior of the furnace to the exterior of the door.

A further requirement of furnace doors for 35 discharging heavy articles, is that the door shall be easily operated by power driven means, without producing excessive shocks, vibrations or jars in the apparatus.

With the foregoing requirements of furnace discharge doors, as well as other desirable fea tures thereof, in mind, I-have invented a furnace door which is not subject to jamming or binding in its frame, because of expansion'and contraction thereof, and which is also provided with means for compensating for any tendency toward warping along the length thereof. A close engagement between the framework of the door and the frame of the door opening in the furnace wall is thus assured under all conditions. The transmission of heat through the door is prevented by insulating the material supporting skids on the inside of the door from the supporting framework on the exterior of the door. Simple and effective operating means are provided for opening the door to discharge material disposed thereon. By reason of the construction to be more fully described hereinafter, this discharge is effected with a minimum of jarring and mechanical shock. I a

In accordance with'the invention, I provide a furnace which, in the illustrated embodiment of the invention, is a normalizing furnace for pipe, with a generally downwardly sloping hearth, provided with skids permitting the easy advancement of the pipe through the furnace. Adjacent the end wall of the furnace, an opening is provided in the hearth extending across the furnace of sufficient dimensions to permit the passage of a pipe laterally therethrough. This door is also provided with skids for receiving and supporting a length of pipe. The framework of the door is supported on links pivoted to the supporting framework of the furnace hearth. A motor driven operating mechanism for opening and closing the door permits easy operation of the device to lower a heated length of pipe from the furnace hearth and discharge itonto a delivery table leading, for example, to a cooling rack. I

For a more complete description of the invention, reference is made to the accompanying drawings illustrating a present preferred embodiment of the invention.

In the drawings,

Figure 1 is a partially broken away longitudinal sectional view through a furnace embodying the invention;

Figure 2 is a sectional view along the plane of line II-II of Figure 1;

Figure 3 is a partial view of the structure shown in Figure 1 to an enlarged scale, showing the invention in one of its operative positions; and.

Figure 4 is a view similar to Figure 3 illustrating a modified form of the invention.

Figure 5 is a partial plan View of the furnace door apart from the remainder of the structure;

Figure 6 is a sectional view along the line VIVI of Figure 5, the refractory lining of the door being removed to disclose more clearly the details of the door structure; and

Figure '7 is a plan view to an enlarged scale of a door section with the lining and skids removed.

Referring now in detail to the drawings and, particularly, to Figures 1 through 3, a furnace 10 comprises a sloping hearth 11, a roof 12 sus pended on hangers l3 and an end wall 14' sup-, ported on a transverse beam 15. The furnace hearth is supported by a structural framework .box castings and the beam 15.

33 are bolted to the box castings 26.

indicated generally at 16. The furnace chamber proper is divided into a heating Zone 17 and a soaking chamber 18.

The articles to be heated in the furnace, for example, lengths of pipe, are introduced endwise at the left hand end of the furnace (not shown) and are permitted, to pass down the sloping hearth 11 under the control of a chain conveyor 19 having fingers 20 projecting up through slots in the furnace hearth. 0n leaving the chain conveyor 19, the pipe lengths or tubes are rolled by hand onto skids 21 on the hearth 11 in the soaking chamber 18. A stop 22 on the skids prevents the tubes from rolling off the ends of the skids.

The furnace hearth 11 terminates short of the 7 end wall 14 and is provided with an end plate 23 having an angularly disposed flange 24. The plate 23, together with the beam 15, define a discharge opening in the furnace hearth extending transversely across the furnace and of sufficient length to permitfthe passage of tubes downwardly therethrough. A furnace door 25 for closing the discharge opening comprises a plurality of box castings 26 having an inclined side wall 26 adapted tocooperate with the angularly disposed flange 24 on the plate 23. The box shaped steel castings 26 are made in short lengths and are bolted together. The ends of adjacent castings rest on arms 27 pivoted at 23 to the hearth supporting frame, and are supported by struts 30 pivoted to the arms at The holes provided in the arms 27 for bolting the box castings 26 thereto are elongated, to permit adjustment to take care of any tendency toward warping which might be encountered.

Since the door 25 is always maintained in proper alinement with the opening in the hearth between. the plate 23 and the beam 15 by the connection of .the arms 27 to the hearth supporting frame, ex-

pansion and contraction of the hearth will not have any effect on the alinement of the door with respect to the discharge opening. Binding and jamming of the door in its frame constituted by the plate 23 and the beam 15 is thus avoided.

Although the inclined side wall 26 of the box castings 26 have but small clearance with respect to the flange 24 of the plate 23, a considerable clearance is provided between the other side of the This clearance permits expansion of the hearth, but the connection of the door to the hearth frame insures that the hearth and door will be displaced to the same extent. Stop castings 32 are bolted to the box castings 26 to close the gap between the sides'of the latter and the beam 15. The bolt holes in these castings are also slotted to permit adjustment of the castings to conform exactly to the alinement of the beam 15. Tube supporting skids Heat insulating pads 34 are provided between the skids 33 and lugs 33 on the box 26 to which they are bolted, as more clearly shown in Figure 6, to prevent transmission of heat through the door 25. A linring 35 of refractory material is provided for the boxes 26.

The operating mechanism for the furnace door 25 comprises a motor 36, a reducing gear 3'7 having a crank 38, a link 39 and a crank 40 on the shaft 41 connected by the link 39 to the crank 38.

nection 43 to the struts 30 for supporting the arms 27 and the castings 26 of the door 25 resting thereon.

The weight of the door 25 and the material, if any, supported thereon, is balanced by a series of counterweights 44 suspended in wells 45 formed in the furnace foundation. Sheaves 46 are supported in suitable bearings seated in the foundation and the cable 4'7 for suspending each of the counterweights 44 passes over the sheaves 46 and is dead-ended on the adjacent strut 30. The struts 39, as shown clearly in Figure 2, consist of a pair of channels 30a and 30b disposed web to web and secured together by any suitable means.

A delivery table 48 is provided adjacent the door 25 and slightly therebelow on a portion of the furnace foundation indicated at 49. This delivery table leads preferably to a cooling rack (not shown).

The operation of the invention will probably be apparent from the description of the apparatus, and the brief outline of the operation already given. The tubes are dislodged successively. from their position of rest inthe soaking chamber and are advanced manually past the ends of the skids 21 and are deposited on the skids 33 forming part of the furnace door 25. The door 25, of course, is normally closed, except when a tube is to be discharged. In such case, the motor 36 is started to produce a clockwise rotation of the crank 38. A similar movement of the crank arm 40 turns the shaft 41 and through the crank arms 42, lowers the struts 30 and the door 25 supported thereon. The door proper, however, is not only given a downward movement by the lowering of thestruts 30, but is also tilted because of the pivotal connection to the top of the struts 30 and to the furnace frame 16 through the arms 27.

Figure 3 shows very clearly the position assumed by the door 25 when the struts have been lowered. It will be apparent from Figure 3 that when the door is in lowered position, the struts 33 thereon are in alinement with the rails constituting the delivery table 18, and that the angle assumed by the skids 33 is such as to cause the tube to roll gently onto the delivery table Without excessive shock or vibration, even though it may be of considerable length and, therefore, quite heavy. When a tube has been discharged from the furnace door, the motor 36 is reversed to raise the door 25 and swing it back to normal position, as shown in Figure 1, in which it tightly closes the opening in the furnace hearth and is then ready to receive another tube for discharge. As before pointed out, the counterweights l4 balance the moving system so that the motor 36 is only called upon to overcome the friction therein.

A modified form of the invention is shown in Figure 4, which is similar in many respects to that already described, but diifers therefrom in that the sections constituting the furnace door are pivoted to the supporting-struts, but are not connected to the hearth supporting frame. ,Stops are provided on the hearth frame for engaging the door when it is lowered, to effect the required tilting thereof to discharge the tube therefrom.

Referring to Figure 4, the furnace hearth is indicated at 50 and the end wall of the furnace at 51. A retaining plate 52 and a supporting beam 53 for the hearth and end wall, respectively, determine a discharge opening which is normally closed by a door 54. The door is somewhat similar in construction to the door 25 of the modification shown in Figures 1 through 3, except that the side walls of the box sections are shaped to fit closely the plate 52 and the beam 53; The

sections of the door 54 are pivotallysupported at 55 on struts 56. Operating mechanism for. the struts 56, similar to that shown in Figure -l, are provided. Stops 57 are mounted on the hearth supporting frame 16 in the path of extensions 58 projecting from the box-shapedcasting sections of the door 54. I

When a tube has been positioned on the door 54, which may be provided with skids 5d, the

lowering of the struts 5.6 will cause the extensions 58 on'the box sections of the door 54 to engage the stops 57. Tilting .movement'ofthe door is thereby effected to discharge the tube from the skids'5 i" to the delivery table indicated 'at 59. As the struts 56 are raised, the door returns to its normal position and is finally closed tightly against the plate 52 and the beam 53.

It will be apparent from the foregoing description that the invention provides a discharge door.

for furnaces which is positively alined with the discharge opening of the furnace hearth at all times, regardless of expansion and contraction of the hearth. The discharge opening, further-' more, is always tightly closed to prevent the 0001- At the same time, ample clearance is provided between the door and the end wall of the furnace *to prevent the necessary expansion of the hearth when heated.

By forming the discharge door of the sectional castings bolted together, the tendency toward warping is minimized, and since the sections are adjustably connected, any slight warping of the individual sections can be compensated for.

1 Since the material supporting skids on the door are insulated from the metallic casing or frame of the door proper, there can be no direct transmission of heat through the door and the skids can,

therefore, be maintained at the temperature of the interior of the furnace.

Since they are made of heat resisting alloy, they are well able to withstand such temperatures. The refractory material within the door castings protectsthe latter I from overheating.

The door operating mechanismis such as to afford a simple and positive control over the movement of the material in the discharging operation and, as previously pointed out, 'excessive shock to the various parts of the equipment is obviated. Summing up the advantages of the invention, it makes possible the discharge of bulky and heavy material from a furnace with a minimum amount of labor and equipment, and at the same time, provides a tight fitting furnace door which will insure thorough and uniform heating of the material in'the furnace.

Although I have illustrated and described herein but a single preferred embodiment of the invention, together with a modification of a portion thereof, I do not intend to be limited to the exact structure disclosed. Numerous changes in the design and construction will obviously occur to those skilled in the art, and any such changes can ,be made without departing from the spirit of the said receiving means.

2. Thecombination with a furnace hearth having a supporting frameworkand material supporting skidsyof a door in the hearth hinged'to saidframework, adapted to receive material from said skids, and means for sw-ingingsaid door on its hinges whereby to tilt it sufiiciently to dis-- charge material carried thereon.

3. A furnace for heating tubular lengths comprising a-he'arth, skids thereon permitting lateral movement of the lengths, a discharge door in the hearth extendingthereacross, skids on the door for receiving lengths from said hearth skids, and means for lowering and tilting said door to discharge lengths laterally therefrom to a receiving means.

4. In a furnace, a hearth, an end wall, a discharge door between the hearth and the end wall, means for maintaining a small fixed clearance between the door and the hearth, there being a substantial clearance space between the door and the end wall to allow for hearth expansion, and

a stop casting carried by the door to close said space when the door is shut.

5. ,A furnace for heating metal lengths having a hearth, a frame supporting the hearth, an open ing extending across the hearth at the discharge end thereof to permit lateral removal of said lengths, and a door for closing said opening consisting of a plurality of metal boxes secured end to end, lined with refractory material and supported on arms pivoted to said frame.

6. In a furnace door, aframe comprising a plurality of alined, box-shaped, castings supported on pivoted arms, a refractory lining for said boxes,- metallic skids for supportingmaterial on the door, and means including heat insulating material for supporting the skids on the frame.

I. In a'furnace door adapted to receive and support heated material, a frame, a refractory lining therein and material supporting means extending above said lining and secured to the frame but separa'tedtherefrom by heat insulatins means. I

8. In a furnace door adapted to receive and support heated material, a frame, and heat-resisting, material-supporting means carried by the door but insulated therefrom.

thereto, means for turning the shaft, and struts extending from said arms to said door.

10. In a furnace, a tilting discharge door in the floor thereof hinged on an axis below said floor, operating means for tilting the door com-' prising struts spaced along the length of the door and extending downwardly, a shaft having cranks thereon connected to said struts, and means for turning said shaft.

11. In a furnace for heating metal lengths, means for feeding the lengths laterally through the furnace, skids for receiving the lengths from said feeding means, a door in the bottom or hearth of the furnace hinged therebelow, V-shaped skids on said door for receiving lengths from said firstmentione'd skids, and means for swinging said door to lower a length positioned on the skids thereof and tilt the door and skids whereby to discharge the length from the door at a level below the furnace hearth.

12. A furnace for heating metal lengths comprising skidsfor supporting the lengths while passing through the, furnace, a door in the furnacefloor or hearth hinged about an axis therebelow,lsaid door having V-shaped skids for re-, ceiving a metal length from said first-mentioned swinging said door to lower the length thereon from the furnace and gradually discharge it at a lower level on tilting of said skids.

14. A furnace for heating metal lengths comprisingia heating chamber, means for supporting metal lengths for movement through said chamber, a door in the floor of said furnace having means constituting a cradle for receiving and holding said lengths in position for discharge, 7

and means for swinging said door to remove the length from the furnace and discharge the length from said cradle on tilting thereof. a

EDGAR I-I. RAY. V

CERTIFEATE {iF CGRRECTION.

Patent No. 1,923,886. August 22, 1933.

EDGAR H. RAY.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 109, claim 6, for "box-shaped, castings" read "metal boxes"; and that the said Letters Patent *should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 24th day of October, A. D. 1933.

(Seal) Acting C mtii iss f if f f Patents. 

